The best day to arrive at Surabaya is Wednesday and it would be best to avoid Sunday, as prices are on average 101.3% higher than on Wednesday. (Average prices, based on 651108 datapoints.)
MondayUS $ 91
Mon
TuesdayUS $ 96
Tue
WednesdayUS $ 71
Wed
ThursdayUS $ 89
Thu
FridayUS $ 80
Fri
SaturdayUS $ 81
Sat
SundayUS $ 143
Sun
Analyse direct flights between Surabaya and Penang.